ghostdog currently rated at 2154. This person has a current challenge accepting only those rated at 1999 and below. This pretty much assures he will win and therefore his rating will falsely increase. In my opinion he is a cheater.
1. Why do you care? 2. Rating is based on probabilities. So you are right: It's more probable for him to win. But the impact of a loss is higher, too. If the rating system is sound that doesn't matter at all.